Gas-responsive means for charging storage batteries and the like



Nov. 2 1926.

J. L. WOODBRIDGE GAS RESPONSIVE MEANS FOR CHARGING STORAGE BATTERIES AND THE LiKE.

Fil y 21, 1924 :5 Sheets-Sheet 1 it'll.

A mil} I MWE/f/TO/ N ov. 2,1926. 1,605,020

J. L. WOODBRIDGE GAS RESPONSIVE MEANS FOR CHARGING STORAGE BATTERIES AND THE LIKE Filed July 21. 1924 3 Sheets-Sheet 2 W asmyu Jim/MEX Nov. 2 1926.

J. L. WOODBRIDGE GAS RESPONSIVE MEANS FOR CHARGING STORAGE BATTERIES.AND THE LIKE Filed July 21, 1924 5 Sheets-Sheet 5 W/ TIYES i I 0 4 WM. w zy w MWLA f m x1 7 7 ORA E Y.

' for example,

. ing current in response means must be provided for allowing this Patented Nov. 2, 1926.

UNITED STATES PATENT OFFICE.

JOSEPH LESTER WOODBRIDGE, 0F PHILADELPHIA, PENNSYLVANIA.

Application filed July 21,

This application is a continuation in part otmy application, Serial No. 324,511, tiled September 18, 1918.

My invention relates to means responsive to the evolution of gas and useful for controlling the charging current of a storage battery.

One object of the invention is to provide simple, sponsive to the rate at which gas is evolved, from one of the cells, or to the pressure produced by the gas, and useful for controlling the charging current of the battery.

It is well known that as the charging of a storage battery progresses a certain amount of oxygen and hydrogren are evolved and the rate at which these gases are produced increases toward the end of the charge if a constant charging rate is maintained. The rate of gas evolution may be reduced by reducing the charging current and it is generally desirable in charging a storage battery to avoid excessive gassing by reducing the charging rate from time totime as the charge progresses; or if a low charging rate is used throughout the entire charge, it may be desirable to maintain this rate constant until the evolution of gas becomes sufliciently rapid and then to interrupt the charging current entirely.

During the earlier part of the charge a certain amount of gas will be evolved at a low rate. which is not objectionable, and in any apparatus designed to control the chargto gas evolution small amount of gas to escape withoutactuating the controlling means. In the apparatus heretofore proposed for accom- -plishing these results, this small amount of gas has beenallowed to escape througha minute orifice to-small thatas soon as gas .is Evolved in anyappreciable quantity the ha i pressure dueto the small orifice would cause an increase of gas pressure in; the cell, and this increase of gas pressure .was relied upon to control the chargingcurrent throu h suitable actuating means. A difliculty arises in the operation of a paratus designed in this way due to the actthat; in oi-derto create anappreciable back pressure'the-orifice must be made exceedingly small and :this orifice-is then reliable and inexpensive means reshown to an enlarged resistance .of the 1924. Serial No. 727,350.

liable to become choked with a particle of foreign material or even with a drop of spray from the cell we drop of condensed moisture, and the slightest obstruction of this kind will stop the escape of gas and increase the gas pressure'in the cell to a point sufiicient to operate the controlling apparatus long before that state of charge is reached at which this apparatus should be caused to operate, thus introducing an element of unreliability which is highly undesirable.

In charging apparatus designed in ac cordance with my invention I have overcome this difficulty by dispensing with this minute gas outlet and providing a liquid outlet or bypass and utilizing the resistance to'the flow of the liquid throu h this outlet as will hereinafter be more fu 1y described.

My invention will be more clearly understood by reference to the following description in connection with the accompanying drawings forming part hereof and in which- Figure 1 is a view, partly in section of apparatus, and partly diagrammatic of circuit connections lnvolvi'ng features of the invent on and designed to vary the charging current of a storage battery in three steps by means of automatically controlled circuit breakers. J

Fig. 2 is a similar, view of apparatus de signed to control a spring driven rheostat in the charging circuit, and

Fig. 3 is a. similarview of a modification of the gas responsive means.-

Referring more particularly to Fig. '1, A is a storage battery of which one cell A is scale and in some detail. The battery 'is' connected across-the charging circuit 1-2 by means of conductors 3-1. Between conductor 4 and conductor 2 are connected three resistors R R and R in parallel relation. These resistors are connected in circuit respectively by means of circuit breakers C C? and C and conductors 10,11 and 33. The construction of the circuit breakerC will now be described, the other two circuit breakers are similar and their corresponding parts will be given the same reference letters but with appropriate exponents. restingon-a pin N holds the circuit breaker in the closed position. The pin N ismount- A laterally projecting arm F the column of liquid in tube 2l upward and out of the tube, when it will fall back on the surface of the stopper 1-9- and be drained off by the lip 24; As soon as the column of liquid has been forced out of tube 21, the gas pressure in the. top of vessel 17 will be relieved and the accumulation of gas will pass off through tube 21 and out;through the orifice 26 in the cover of the-vessel 16. The gas pressure being relieved, the liquid will be forced back from the'vessel 16 lnto vessel 17 through the orifice 18 by reason of the difference/1n head of the liquid inithe two vessels until the l vel in the vessel 17 rises to a point where the lower end ofgtube 21 is again closed,- Further accumulatwn of gas pressure will themggi rce another column of liquid up intdftubef 2K? and the cycle-will be repeatedp' Y So long as the evolution of "gas ffcjitithe cell A is com aratively slow the level of the liquid in tu e 21 and in the outer {vessel 16 will be approximatelylthe same ifsince there is free communication'between the two bodies of liquid through the orifice 18"and the upper end of the tube 21 communicates freely with the space over the liquid in vessel 16. The quantity: of and the dimensions ofthe latter should be such that under. these conditions as the gas pressure slowlyincrcases, a suflicient quan' tity of liquid is forced out of the vessel 17,

through orifice 18 to break the columnot liquid at the bottom of tube21 before the 1 column rises sufiicientlyxto make contact at the top with the terminal 27. If; however, the evolution of gas in cell A is sufficiently rapid, the liquid will nbt be able to pass through the. small rifice'18 fast enoug to maintain equilibrium, but considerable back pressure Wlll be causing the column of liquid in tube 21 to rise to a higher level than'the surface of the liquid in vessel 16. I u i The more rapid the development-of gas in cell A becomes the great "'1' willbe this difference of level and the apparatus may be so designed that with a given rate bf evolution of gas in the cell A the column of liquid in tube "21 will rise to a sufficient hei htto m e contact at itsupper surface wit terminal 27 before broken at the lower end of the tube. When this occurs the'ci'rcuit of th gexciting coil 14 will be closed by reason of ithe continuous body of conducting liquid between terminals 27 and 28 through orifice 18 and the column of liquid in tube 21, and" the relay 13 will make contact, thereby ermitting currentto pass through trip coil and tripping open the circuit breaker G This will-cut out of circuit'resi'stor R andreduce the charging current passing through the battery'A. On account of this reduction in charging current .the rate of evolution of gas in cell position liquid in the vessels developed at this point,-

the column is utilized for controlling a A will be reduced but the battery will continue to charge at the lower rate.

When the circuit breaker C is tripped, as described above, by the movement of the lever L caused by the attraction of the solenoid T the lower end of the lever is moved to the right thus opening the contacts at 41.' The opening of the circuit breaker will also open the contacts at 5 thus introducing the resistance S in series with the solenoid The resistances is so designed that the reduced value of the current in solenoid T withthe resistance S in circuit, while in-' sufficient to start the motion of lever L against the tension of spring-V will still be 's'uiilcien't to hold the lever in the open after it has been ,drawn over, on account ofithe reduction inthe' air gap of the solenoid T so that the closing of the contacts 6 by reason of the opening of cireuit breaker G, will not 'close the circuit of the solenoid T until the contacts at 41 are again closed, v This will only occur when the relay 13 opens upon the opening of the circuit in the device by the breaking of the column of liquid in the tube 21 at its lower end. When this occurs and the relay 13 opens, the liver L will bereleased and the contacts re ored at 41. The relay 13 now being open, no current will flow through the solenoid T until a further increase in the rate'of gas evolution occurs in the cell A sufiicient to re-establish the circuit in the apparatus K, as described above. When this occurs, the relay 13 will again close, this time tripping circuit breaker and opening the circuit of resistor R causing a further reduction in the charging current of the battery. When the rate of gas evolution again rises in the cell A, the circuit breaker C will be tripped open, thus breaking the charging circuit cut ting off the charge. a I

Itwill be seen that the apparatu above described provides means for controlling the charging current o fflie battery in response to the rate of evolution of gas and the accumulation of gas pressure in the cell A andit will further be evident that the tube 21 is a controlling element in which liquid rises in response to gaseous pressure and the orifice 18 is a relatively restricted liquid outlet which limits the rise of liquid in the element 21 at low rate of gas production. Hence the invention is not limited to the particular embodiment of. those 'elements shown and described.

-" In Fig. 2 is apparatus illustrated in Fig. 1. in which the device responsive to gas pressure is spring driven rheostat. As in 1, the battery"to be charged is shown at A. with one 'cell A shown more in detail, and the battery is'connected across the circuit 1-1-2, through a irely and cutshown a modification of the v number of resistors R to R connected in parallel. These resistors are respectively connected to contact terminals or brushes B to Il which bear upon a contact piece 43 a mounted on an insulating sector 44 which is designed to rotate about an axis 45. A contact terminal 46 connected to conductor 2 also bears upon the contact piece. 43, thus connecting battery A to the conductor 2 10 through conductor 4 and the resistors R to R Rotation of the sector 44 in the direction of the arrow will cut out the res stors R etc., one by one as the contacts between the corresponding brushes 13' B etc., and

15 the contact piece 43 are successively broken.

10 same axis are rigidly mounted a ratchet wheel 47 and a crank handle 48. On the same axis is also rotatably mounted a gear wheel, whose tooth pitch line is indicated by the cir cle'34 This gear wheel carries a pawl 49 engaging with the ratchet wheel 47, so

that the sector 44 cannpt be revolved by the tension of the pring 39, except by driving the gear wheel 34.

[The gear wheel 34 engages a pinion'37,

30 mounted on the same axis with another gear wheel 35, and the latter engages a pinidn 38 on whose axis is also mounted a fan 50 and a brake-wheel 36. 'A brake shoe 5l car ried on an arm 53 is held against'the periphery '55 of the brake wheel 36 by means of the spring .52.. The arm 53 carries at its upper end an armature 54 arranged to be attracted by the magnetic eore of thesolenoid 55. This so-f lenoid is connected between conductors 1 and 40 4 through the contacts of the relay 13.- The.

.the relay 13 and closing its contacts. will energize solenoid 55 which will attract operation of the relay 13 "iscontrolled by means of the gas control device K, which is identical in its" construction and mode of operation with that shown in Fig; 1 and-dc scribed above.

When the evolution of gas in the cell A is sufiiciently rapid, the circuit will be closed in theapparatus K, energizing This the armature 54 and release thebrake shoe 51 thus permitting the gear train to revolve at a speed limited bythe fan 50. Thesec-i tor 44 .will, therefore, rotate in the direction of the arrow for a short distanceuntilthe 55 contact in the apparatus K is o ened, when the brake 51 will be applied to t e wheel 36,

v and the motion of the geartrain will be stopped. In this way the sector 44 will be moved intermittently inxthe direction of'the,

arrow, gradually cutting out the resistors R k to R- the operation being controlled by the rate of evolution of gas in the cell A Whenthe last resistor R 1s cutout of circuit, the

charging of the battery will be entirely. in-

' terrupted. The device may be reset for r peating the above described performance by turning the crank handle '48 to the right bringing the sector 44 back to the position shown, and rewinding the spring.

In Fig. 3 is shown a modification of the gas control apparatus shown at K in Figs. ,1 and 2, but designed to be non spillable. It consists in a vessel K provided with a threaded projection at the bottom,'desi ed to be screwed into the vent opening 64 o the storage cellJA The vessel K shown in section, is made of insulating-material such as hard rubber. -This vessel is provided with a inner cylindrical chamber 60, closed at the to by a cover 61, and provided with a tubular extension of the bottom 62, closed at its. lower end by a conducting iece 63, screwed into a threaded opening at t e bottom of the tube 62 and projecting downward to make contact with the electrolyte in the cell A Surrounding the inner chamber 60 of the vessel K is an annular space 65, from which on the lefthand side there projects downwardly a'tubular opening 66. A horizontal thrcadcd'hole 67 is shown passing across the ,opening 66 and into the opening,62 at the bottom of the inner chamber 60. In this hole is screwed a threaded plug68 which has a finehole 69 running axially, and another 70 arranged transversely and crossing the hole 69. Thus through the two holes 69 and 70 restricted communication is established between the inner chamber 60 and the external space 65. 4

' In the cover 61 is inserted a tube 71 extending downwardly into the chamber 60 to a point just above the top of the tubular opening 62. Around the tube 71 extends an extension of the cover 61 in the form of a sleeve 72, there beingva small clearance between this sleeve and the tube 71 from the lower end of the sleeve up to a point near the upper surface of the cover, beyond which point the tube 71 makes a tight fit with the cover. horizontal hole 73 near the lower surface of the cover communicates at one end with the clearance space between the tube 71 and the sleeve 72, and at theother end with a circular groove 74 'on the under side of the coveri A small duct 75 in the wall offthe chamber 60 communicatesat its upper end with the groove 74 and at its lower end with the spac'eover the electrolyte in the cellA. The vesselK is provided with an upper cover 76, in which is mounted a conductin terminal -77, which extends through the cover to a point just above the upper end of the tube-71. The conducting terminal 7 7 is connected by conductor '80 to, the coil 14 ofrelay 13, andthence byzconductor 81 to'the opposite end oftlie battery 'A. On the'under side of the cover 76 is arranged a cylindrical b aflle 78 surrounding the cOn-Q.

ducting terminal 77 and provided withv vents 79 communicating at their-lower ends with K v v 4;

downwar the space 65, and at their upper ends with the external atmosphere. At'the bottom of the chamber 60 and of the space 65 there is a small quantity of conducting liquid such as dilute sulphuric acid.

The design is such that if the vessel K inverted, the liquid in the chamber 60 will be retained in the space between the cover 61, the outer wall of the chamber and the sleeve 72; and any liquid in the space 65 will be retained by thecover 76, in the space be tween the baifie 78 and the outer wallof the vessel K so that no liquid can escape in whatever position the vessel K may 'be placed. The operation of the device shown in Fig.1 3 is the same as that of the apparatus Figs. ferently arranged. The gas pressure'fl developed in the cell A as the chargegrogresses, will force the gas through the 7 5' and the groove 74, and thence through v the passage 7 3 and downward through the clearancespace betweenthe tube 71" and the sleeve 72 into the inner chamber 60. This gas pressure will force the liquid in the bottom {of the chamber up through the tube 71, and also through the' restricted vent 69 and 70 into the space- 65. v If the rate of gas evolution. is cemparatively slow, the rise of liquid in'the space 65,.and in the tube 71 "will be; sub stantially equal, and the total volume of liquid is such that under these conditions a sufficient amount of liquid: will be forced out into the space to lower the level of "the liquid in the chamber '60 to a point where the column of liquid in the; tube '71 will be broken atthe bottom before its rises far enough to make contact with the terminal 77 at the top.; If, however, the rate of gas evolution is'm'ore rapid, the restriction of flow through the vent 69 and 70 will be such as to permit. the column of liquid inl the tube 71 to .rise to- .asufiicient height to make contactwith' the terminal 77 before the column is broken at the bottom. 7 This will establish a. circuit from the electrolvte in the cell .A. throughjth'e contact point (i3 and the liquid-in the chamber 60 and in the tube 71 via terminal 77 and conductor 80 through the coil 14 and thence via conductor 81 to the opposite terminal of battery A, thus causing current? to flow through the coil 14 and actuate the relay 13, ,This relay may thenbe used to controlthe charging circuit of the battery as' shown in Figs. 1 and 2 or in any other obvious manner.

'jlhe design of the screw plug 68i'sof advantage in permittingfthe apparatus to be adapted to control for different rates of charge. 'For example, if it is desired to allow the chargingrate to reach a higher value before the apparatus K acts to re.-

1 and 2, the parts being SOIHGWhfltdlfsure duce the rate, the plug 68 may be removed and another plug substituted having the vent 69 of. slightly larger diameter. It will then be necessary for the *rate of gas evolution to reach a higher value before the restriction to fl in the vent 69 'is sufficient to cause the column of liquid in the tube 71 to complete the circuit and operate the relay 13. On the other hand, if itis desired to control for a lower value of charging current, 'a plug may be used whose vent 69 has a smaller diameter thus causing the ap aratus K to respond to a slower rate of gas evolution.

It will be noted the circuit in the apparatus K and K takes place in a mixture of explosive gases, oXy en and hydrogen. I have found, however, t iat if the reactance of this circuit is kept below a certain point and the current is kept below a certain value, there will be no danthat the interruption of terrupted. I have found that with a coil on the relay 14 having a resistance of 12 l ohms and an impedance of approximately 75 ohms at"60 cycles and requiring ,a current of less than 0.15 ampere to operate the relay, the apparatus can be used successfully with out any danger ofexplosion.

Having described my invention, what I claim and desire to secure by Letters Patent is: 4

1. In controlling means responsive to gas pressure, the combination of two receptacles adapted to contain liquid and communicating with each other by a passage adapted for restricted flow and whereof one is provided with a vent, means for applying gas presto the liquid in the latter to'force it through the vent, and controlling means responsive to the difference in rate of liquid flow through the vent and said restricted passage.

2. In controlling means responsive to gas pressure, the combination of two receptacles adapted to contain liquid and communicate ing with each other by a passage adapted for restricted flow, and whereof one has a vent, opening below the normal liquid level, I

means for applying gas pressure above the liquid level in the last named receptacle whereby 'l iquid. is forced through the vent and the passage, and-controlling means responsive to the quantity of liquid forced iing with each otherby a passage adapted.

for restricted flow; and whereof one has a vent, said vent opening below the normal hquld level and discharging into the other, means for applying gas pressure above the liquid level in the last named receptacle I whereby liquid is forced through the-vent and the passage into the other receptacle, and controlling means responsive to the difference-in the rate of flow through the vent and the passage.

4. In apparatus for controlling the charge of a storage battery, the combination of two liquid receptacles communicating by a passage adapted for restricted flow, a vent tube opening below the normal liquid level in one of said receptacles and discharging into theother, means for applying to the first named receptacle .gas pressure developed by the evolution of gas in one of. the battery cells, whereby liquid is forced from said receptacle through the restricted passag'eiand the vent into the other receptacle, andmeans responsive to the difference in rate of flow throu h said vent and passage for controlling t e batte charge.

5 In control ing apparatus responsive to gas pressure, the combination of a liquid receptacle having two outlets whereof the first is a vent adapted to permit liquid or gas to escape depending upon the liquid level and whereof the second is an orifice below the liquid level of comparatively restricted section; means for applying gas pressure outlet.

above the liquid level, and controlling meansresponsive to the volume of liquid forced to flow through the vent by said pressure bcfore said flow is interrupted by reduction of 1? .uid level. I

6. n apparatus for controlling the charge of a storage battery responsive to the rate of gas evolution in one of the cells, the combination of a liquid receptacle-having an outlet of restricted section below the liquid level, means for applyihg the pressure of the gas to cause the liquid toflow through said outlet, and controlling means responsiveto the retardation of flow through said 7. In apparatus for controlling the charge of a storage battery, the -combination of two -liquid receptacles communicating by a pets 1 sage adapted for restricted flow, a vent tube opening below the normal liquid level in one of said receptacles and discharging into the other, means for applying to the first namedrecepta'cle gas pressure developed by. the evolution of gas in one of the battery cells whereby liquid is forced fromsaid .re'T ceptacle through the restricted passage" and the vent into the other receptacle, and means for controlling the battery charge including an electrical circuit having a contact in the of a storage battery, thecombination of a;

receptacle containing liquid and provided with two outlets of'different section, .means for applying'above the liquid pressure developed 1n one of the battery cells to force the liquid tlirqugh the two outlets, and controlling means responsive. to the difference in rate of flow through the two outlets.

10. Controlling means responsive to gas pressure and comprising the combination of a pressure chamber adapted to contain liquid 'and havin in communication with it opposed fluid columns normally in" restricted communica ion causing substantially equal rise of lev l in both columns under slowly increasing pressure and increased rise of level in one of the columns under quickly increasingrp'r'essure, and-controlling apparatus responsiye to such increased rise, substantially as described.

1 1, Controlling means responsive to gas pressure/and comprising the combination of a pressure chamber adapted to contain liquid and having in communication with 1t opposed .fiuid columns in which the level rises equally under slowly increasing pressure and unequally under rapidly increasing pressure, and controlling apparatus res onsive to such difference in rise, substantially as described. 12. Controlling means responsive to evolution of gas comprising a rece tacle containing liquid, and having a restricted outlet below the liquid level, means forac'cumulating and confining gas in the receptacle above the liquid, and controlling means responsive to the difference between the. rate of gas accumulation and the rate offiowithrough theout-let.

J. LESTER WOODBRI/DGE. 7 

